Serum Creatinine (Creatinine, Kidney Function)

What Does Creatinine Measure?

Creatinine is a byproduct of muscle breakdown and is naturally excreted by your kidneys. Elevated levels may indicate reduced kidney function, while lower levels could suggest overhydration or muscle loss. This test is often used alongside other markers to evaluate kidney health.

Why Is This Test Done?

Your healthcare provider may order a serum creatinine test to monitor kidney disease, diagnose conditions like chronic kidney disease, or assess how well medications are being processed by your kidneys. It’s also used in the evaluation of dehydration, muscle disorders, or fluid imbalances.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab for analysis. No special preparation is needed, but you may be asked to fast or avoid certain medications for a day or two before the test.

What Are Common Results?

Results are typically reported in milligrams per deciliter (mg/dL) or micromoles per liter (µmol/L). While reference ranges vary by lab, higher than expected levels may signal kidney problems, while lower levels could raise concerns about hydration or muscle mass.